type Mytype = string | number;
let obj: Mytype = undefined;

// type 多用于关系类型

interface Person {
  name: string;
  age: number;
}
interface Son extends Person {
  father: Person;
}
let father1: Person = { name: "lwt", age: 15 };
let son1: Son = {
  name: "lhh",
  age: 15,
  father: father1,
};

// interface 多用于数据结构
export {};


